DESCRIPTION: The application describes plans to continue to investigate incidence, risk factors, and outcome in late-life dementia, including Alzheimer's disease, in a prospective, community-based study (the MoVIES project) of a low-SES, rural elderly cohort in the mid-Monongahela Valley of Southwestern Pennsylvania. The cohort was assembled between 1987 and 1989 and has been followed since then with biennial waves of cognitive and risk factor screening, interspersed with multi-stage clinical evaluation. This well-characterized cohort, with low attrition rates, numbered 981 at the beginning of the current (fifth) wave and will be aged 74+ at the start of the proposed continuation. Working closely with the University of Pittsburgh Alzheimer's Disease Research Center, standardized assessment protocols and diagnostic criteria have been used to identify 135 incident cases to date. The plan is to follow up several promising leads with respect to risk factors, and have particular interest in two of them: thyroid dysfunction and the apolipoprotein E (ApoE) genotype. The current plan is to accrue a total of 236 incident cases by the end of the proposed study period. The Specific Aims are: 1) to estimate and compare incidence rates across groups defined by demographic and selected risk/protective factors; 2) to identify risk/protective factors for incidence of dementia and subtypes of dementia, and for cognitive decline, including, but not limited, to the ApoE genotype and thyroid dysfunction; 3) to determine cognitive norms for cognitive stability/change over time, identifying predictors of cognitive decline and patterns of decline predictive of dementia; 4) to estimate rates of selected outcomes (mortality, institutionalization) in dementia and subtypes of dementia; and 5) to identify risk (prognostic) factors for mortality and institutionalization in all dementias, and in subtypes of dementia, compared with the overall cohort.